1. Field of the Invention
The present invention relates to a golf club head. More specifically, the present invention relates to an iron-type golf club head having movable mass members.
2. Description of the Related Art
The prior art discloses various iron-type golf club heads. Irons are typically composed of a stainless steel or titanium material, and are typically cast or forged. Most golfers desire that their irons have a large sweet spot for greater forgiveness, a low center of gravity to get the ball in the air, a solid sound, reduced vibrations during impact, and a trim top line for appearance. Unfortunately, these desires are often in conflict with each other as it pertains to an iron.
Most existing irons, both those intended for play or for fitting, do not have adjustable weights in the head. Those few that do have adjustable weights have several disadvantages. First, the amount of moveable weight is inadequate to meaningfully affect mass properties in both heel-toe and up-down directions. Second, the weighting elements detract from the visual appeal of the head. For example, the weights can be seen at address and are distracting during a golf swing. Third, the weighting elements detract from the sound or feel at impact with a golf ball. Fourth, the weighting elements loosen during use.
Most iron-type golf club heads are designed with specific mass properties that cannot be adjusted.
One example is U.S. Pat. No. 5,228,694 to Okumoto et al., which discloses an iron club head composed of a stainless steel sole and hosel, a core composed of a bulk molding compound or the like, a weight composed of a tungsten and polyamide resin, and an outer-shell composed of a fiber-reinforced resin.
Another example is set forth in U.S. Pat. Nos. 4,792,139, 4,798,383, 4,792,139 and 4,884,812, all to Nagasaki et al., which disclose an iron club head composed of stainless steel with a fiber reinforced plastic back plate to allow for weight adjustment and ideal inertia moment adjustment.
Another example is U.S. Pat. No. 4,848,747 to Fujimura et al., which discloses a metal iron club head with a carbon fiber reinforced plastic back plate to increase the sweet spot. A ring is used to fix the position of the back plate.
Another example is set forth in U.S. Pat. Nos. 4,928,972 and 4,964,640 to Nakanishi et al., which disclose an iron club head composed of stainless steel with a fiber reinforcement in a rear recess to provide a dampening means for shock and vibrations, a means for increasing the inertial moment, a means for adjusting the center of gravity and a means for reinforcing the back plate.
Another example is U.S. Pat. No. 5,190,290 to Take, which discloses an iron club head with a metal body, a filling member composed of a light weight material such as a plastic, and a fiber-reinforced resin molded on the metal body and the filling member.
Another example is U.S. Pat. No. 5,411,264 to Oku, which discloses a metal body with a backwardly extended flange and an elastic fiber face plate in order to increase the moment of inertia and minimize head vibrations.
Another example is U.S. Pat. No. 5,472,201 to Aizawa et al., which discloses an iron club head with a body composed of stainless steel, a face member composed of a fiber reinforced resin and a protective layer composed of a metal, in order to provide a deep center of gravity and reduce shocks.
Another example is U.S. Pat. No. 5,326,106 to Meyer, which discloses an iron golf club head with a metal blade portion and hosel composed of a lightweight material such as a fiber reinforced resin.
Another example is U.S. Pat. No. 4,664,383 to Aizawa et al., which discloses an iron golf club head with a metal core covered with multiple layers of a reinforced synthetic resin in order to provide greater ball hitting distance.
Another example is U.S. Pat. No. 4,667,963 to Yoneyama, which discloses an iron golf club head with a metal sole and a filling member composed of a fiber reinforced resins material in order to provide greater hitting distance.
The prior art fails to disclose an iron-type golf club head that has a multitude of mass property combinations without the afore-mentioned disadvantages.